Anatomy Lecture 3 Flashcards Preview

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Flashcards in Anatomy Lecture 3 Deck (38):
1

What is the purpose of the stay apparatus of the horse?

Allows the horse to dose while standing up, using minimal muscular activity
- locks joints and limbs to prevent collapse

2

What is another name for the shoulder joint?

Glenohumeral joint

3

What is another name for the elbow joint?

Humeroradioulnar Joint

4

What are the names of the three joints in the Knee?

Antebrachiocarpal Joint
Intercarpal Joint
Carpometacarpal Joint

5

What is another name for the Fetlock?

Metacarpophalangeal Joint

6

What is another name for the Pastern?

Proximal Interphalangeal Joint

7

What is another name for the Coffin?

Distal interphalangeal joint

8

What are the muscles involved in the Fibrous support mechanism?

Tendon of the Biceps brachii, Lacertus fibrosus, Extensor carpi radialis, Triceps brachii, SDF and accessory (proximal check) ligament, DDF and accessory (Distal check) ligament, Common digital extensor tendon, Interosseus, Proximal sesamoid bones and sesamoidean ligaments.

9

The tendon of which muscle prevents the shoulder from flexing (stay apparatus)? How?

Biceps brachii - radial insertion of this muscle is a fixed point since its close to the axis of rotation of the elbow which is stabilized by the weight of the animal.

10

What allows the shoulder joint to lock (stay apparatus)

Molding of the biceps brachii tendon to the intermediate tubercle of the humerus

11

What acts to maintain the extension of the elbow when the actual muscle of the triceps brachii is flaccid? (stay apparatus)

The fibrous components within the muscles maintain extension

12

What muscle at the elbow joint remains engaged during the stance phase?

the anconeus

13

With the shoulder fixed, how does the weight rest?

on a nearly vertical radius

14

How is the stabilization of the shoulder achieved?

- biceps brachii maintains extension of the shoulder

15

How is the stabilization of the Elbow joint achieved?

- fibrous components within the triceps brachii maintain extension of the elbow
- Anconeus remains engaged during the stance phase
- smal corrections made by the carpal and digital flexors to maintain vertical radius of weight

16

How is the stabilization of the Carpus achieved?

- tension exerted on the tendon of the biceps brachii is transmitted to the extensor carpi radialis m. via the lacertus fibrosus. This exerts overall upwards force that prevents buckling
- Strong palmar carpal ligament also prevents hyperextension

17

Which muscles are involved in the stabilization of the fetlock, pastern and coffin joints?

- Suspensory apparatus: Interosseus (lateral and medial branches that unite with comon digital extensor), proximal sesamoids, sesamoidean ligaments (Straight, Oblique, Cruciate)
- SDF and proximal check ligament
- DDF and distal check ligament

18

How is the downward force on the SDF and DDF counteracted?

by the proximal and distal check ligaments respectively

19

What counteracts the flexing of the coffin joint?

the extensor branches of the interosseus

20

What counteracts the hyperextension of the fetlock?

the distal sesamoidean ligaments

21

Where do the distal sesamoidean ligaments attach?

distal attachments to the proximal phalanx, middle phalanx also attached to the middle phalanx

22

How are the structures of the suspensory apparatus able to "spring back" to their normal state so quickly?

they store energy

23

What is a digigrade?

walks/bears weight on digits

24

What is an Unguligrade?

walks/bears weight on the distal phalanx

25

What metacarpal bone is weight bearing in the horse?

the third metacarpal

26

What metacarpal bone is weight bearing in the Ox?

Third and Fourth metacarpals

27

Which metacarpal bones are the medial and lateral splint bones of the horse?

Medial: second metacarpal
Lateral: Fourth metacarpal

28

Which carpal bones are fused in the dog?

the radial and intermediate proximal carpals

29

Which carpal bones are fused in the horse?

The first distal carpal is either fused, very tiny, or non-existant

30

Which carpal bones are fused in the Ox?

The second and third distal carpal bones are fused and the first is missing

31

What muscle gives the horses shoulder a nice rounded appearance?

the subclavius m.

32

Which muscle on the horse forms the ventral border of the jugular groove?

the sternomandibularis m. (synonymous with the sternocephalicus)

33

Which digits are cut when amputating the digit in cattle?

the proximal and distal interdigital ligaments

34

What muscle has ruptured in a horse with a flying scapula?

serratus ventralis

35

Carpal bone II rests entirely on what?

the medial splint bone

36

Carpal bone IV rests on what?

both metacarpals III and IV

37

Where do popped splint lesions in the forelimb usually occur? What does it result in?

on the medial side - results in damage to the interosseus ligament

38

How are proximal sesamoid fractures accomplished?

the accessory bone gets pulled on so hard that pieces of bone rip off